United Nations warns against sabotaging Syria talks in Geneva

But before leaving, the head of the Syrian delegation said he would not return unless the opposition withdrew its objection to Syrian President Bashar-al-Assad playing a role in a future government of transition.

The United States and France called on Russian Federation on Wednesday to deliver the delegation of President Bashar al-Assad to Syria peace talks in Geneva after discussions on ending the six-year war resumed with no sign of the government attending.

The mediator of United Nations -led Syrian peace talks in Geneva will assess next week whether either side is trying to sabotage the process, he said on Thursday, after President Bashar al-Assad's negotiators said they would turn up five days late. The delegation quit the talks Friday to, as it said, "consult and refresh" with Damascus.

"So now, it is the responsibility of the worldwide community, it is the responsibility of the United Nations and the special envoy, to announce to the world who is the party who is rejecting the negotiation".

De Mistura says he has been informed by the Syrian government delegation that it will rejoin the peace negotiations on Sunday. "If they are quite serious about bringing peace to Syria, well they should show up". The Syrian government said it is mulling a return to Geneva, following a short break.

Most serious of all, the United Nations reports the government still refuses to permit the medical evacuation of almost 500 critically ill and wounded people from Eastern Ghouta, a besieged suburb of Damascus.

Syria's opposition has insisted that Mr Al Assad must step down, but his negotiators have refused to discuss the issue and the regime's recent successes on the battlefield have strengthened his hand.

He said the Geneva rounds of talks were the only peace process backed by the U.N. Security Council, although there were many other initiatives being planned.

Jaafari described that position as "provocative" and "irresponsible", warning that "there will be no progress" if the opposition maintained that position.

The Islamic State group claimed Tuesday's attack in Akarma, a government stronghold south of Homs.

Syrian state TV has aired images of the van's charred body, as well as damaged vehicles nearby. There was no immediate Israeli comment.

SANA says the attack occurred early on Tuesday but hasn't said whether there were casualties.

The opposition's Britain-based Syrian Observatory for Human Rights reported late on Monday the Israeli airstrike on the Damascus suburb of Jamaraya.

The alleged Israeli missile attack came three days after Syria said Israel fired several surface-to-surface missiles at a military post near Damascus, causing material damage but no casualties.

Though Israel has mainly stayed out of the conflict in neighboring Syria, it has carried out a number of airstrikes against suspected arms shipments believed to be bound for Lebanon's Hezbollah militant group, which is fighting alongside President Bashar Assad's forces.